BugTraq
Multiple Vulnerabilities In OpenBB Apr 25 2004 08:25AM
JeiAr (security gulftech org)


Vendor : OpenBB Group

URL : http://www.openbb.com

Version : Open Bulletin Board 1.0.6 && Earlier

Risk : Multiple Vulnerabilities

Description:

OpenBB is a fast, lightweight, powerful bulletin board written

in PHP/MySQL. Main features include: full customization via styles

templates, instant messaging, private messaging, categories, member

ranks, poll based threads, moderation, BB codes, thread notifications,

Avatars, member lists, private forums and more.

Cross Site Scripting:

OpenBB is prone to Cross Site Scripting in multiple files. This may

allow an attacker to run code in the context of a users browser, or

used to harvest sensitive information from a user such as cookie

information. Below are some examples of the XSS issues in OpenBB.

/member.php?action=login&redirect=[XSS]

/myhome.php?action=newmsg&to=blah[XSS]

/post.php?action=mail&TID=1[XSS]

/index.php?redirect=[XSS]

SQL Injection:

It may be possible for an attacker to execute arbitrary SQL queries

due to user supplied input not being properly sanitized. Lets have

a look at some code from one of the affected files ... post.php

// Check to make sure they are not posting to a category

$query_type = new query($SQL, "SELECT type FROM ".$prefix."forum_display

WHERE forumid = $FID");

$query_type->getrow();

$ftype = $query_type->field('type');

As we can see from this code, the $FID variable seems to get passed

directly to the query without being validated, thus allowing for

an attacker to execute malicious queries. This is not the only

vulnerable file though. Below are a list of similarly vulnerable

files.

/board.php?FID=1[SQL]

/member.php?action=list&page=1&sortorder=[SQL]

/member.php?action=list&page=1&sortorder=username&perpage=[SQL]

/member.php?action=passwdsend&resetid=blah&id=2[SQL]

/search.php?&sortby=dateline&sort=DESC&q=open&forums%5B[SQL]%5D

/post.php?action=edit&page=1&PID=1[SQL]

/post.php?action=post&FID=1[SQL]

These files are prone to similar attacks because they allow input

that has not been validated to be executed in the query. This can

be used for example to pull users password hashes.

Arbitrary Command Execution:

This is really in my opinion at least, a very fundamental flaw. As

stated in the HTTP/1.1 RFC (RFC 2616 Section 9.1.1 "Safe Methods")

no GET request should be used to make any significant actions. This

however would not be such a big deal if there was some sort of auth

key or session id in place to verify the validity of actions, but

there isn't. In short all an attacker has to do is send an admin a

pm, or make a malicious post with the desired command and the action

will silently execute. For example below are some example administrative

actions thatan attacker could include in an image tag or malicious link.

/cp_forums.php?do=remove&id=1

/cp_usergroup.php?do=remove&UGID=1

/cp_ipbans.php?action=do_delip&ipid=1

This kind of attack can also be used to run user and moderator

commands as seen below. These are only examples, not all the

possibilities.

/myhome.php?action=delmsg&box=inbox&id=all

/post.php?action=edit&PID=1&send=1&delete=yes

/moderator.php?action=announce&TID=1

OpenBB actually tries to prevent these kind of attacks by filtering

out certain input as seen in /lib/codeparse.php but this does not

work. Lets have a look at the code.

case 'img':

if(!preg_match('#^(http|https)://(.*?)\.(gif|jpg|jpeg|png)$#', $inside) )

$return = '[ invalid image ]';

else

$return = '<img src="' .str_replace('"', '', $inside). '" alt="User-Posted

Image (tm)" border="0" />';

break;

All an attacker has to do in order to have the command executed

successfully is make sure the url within the image tag ends with

an allowed extension. This is not very safe at all because we can

make up a variable, add a good extension and the code is still ran.

For example

/post.php?action=edit&PID=1&send=1&delete=yes&image=blah.jpg

As we can see from the above examples, this issue can be used by a

malicious person to all but completely sabotage a site running

OpenBB. In the past I have seen phpBB for example deal with the same

issue of using unsafe GET requests by limiting the bbcode to only

allow images with a valid extension. However this is a bad idea

because it does not solve the problem at all, and to this day all

phpBB versions are vulnerable to having arbitrary posts deleted and

more just by visiting a malicious web page or link. It is a serious

issue and should be treated as such. It greatly impacts the security

of a web application. Even using the POST method without an auth key

or the like is a bad idea

in my opinion.

Other Issues:

These other issues I am about to describe have been discovered by a

guy named Manuel Lopez mantra (at) gulo (dot) org [email concealed] and asked me to include them

in this OpenBB write up.

/* Snip */

Hi JeiAr, I am Manuel.

I have just read your post in OpenBB.

At March 24 2004 I alert Stu about some vulnerabilities that I have found on

March 20 2004, Stu

tell me .. "A verson 1.0.7 will be released ASAP".

I was having in mind publishing an advisory as soon as Stu released the new

version.

/* Snip */

The issues are in the avatar feature and pm feature. From what I

understand a user can read arbitrary PM's just by specifying the

message id. For example the url might look something like this.

http://forum/myhome.php?action=readmsg&id=INT&box=inbox

Where "INT" is there would be an integer specifying the message ID.

The other issue discovered by Manuel is the fact that you can upload

any file as an avatar. While this does not allow for php, or server

side code execution, it does allow for client side code (such as JS,

VBS, etc) to be executed. The uploaded code will then be available at

the following url once uploaded.

http://forum/avatars/[usernamehere]avatar_type

Once again, just want to specify the last two vulnerabilities were

discovered by Manuel Lopez and not myself, he just asked if I would

include them :)

Solution:

Vendors were contacted many weeks ago and plan to release a fixed

version soon. Check the OpenBB website for updates and official

release details.

Original advisory can be found @ http://www.gulftech.org/04242004.php

Credits:

Credits go to JeiAr of the GulfTech Security Research Team.

http://www.gulftech.org

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